Dougie Freedman’s side, who have now lost their last three games, went ahead when midfielder Ben Osborn fired a low shot past goalkeeper Richard O’Donnell.

But Jonathan Kodjia tapped the visitors level after Joe Bryan’s effort had come back off the post.

And City, who struck the woodwork again through Nathan Baker, completed the turnaround thanks to Flint’s header.

The Robins had seen their 100% start under new head coach Lee Johnson emphatically ended by Brighton on Tuesday, but victory at the City Ground was their fourth in five games and maintains the eight-point gap to the relegation zone.

Forest, who had gone 13 Championship matches unbeaten prior to recent defeats by Huddersfield and Burnley, have now slipped to 13th in the table.

But Kodjia’s strike moments before half-time and Flint’s near-post header with 20 minutes left secured victory for City, who had not overturned a deficit to win since the final day of last season.

Nottingham Forest boss Dougie Freedman:

“The performance was good, in the first hour in particular. We deserved the lead and we had chances to make it a bigger lead.

“It was a setback losing Jamie Ward to injury and then to lose the goal just before half time, when the ball bounced back off the post right to their player.

“We started the second half very well. But the issue was that we made the wrong decisions in front of goal. In the end, we lost our discipline when we were chasing the game. On top of that, if you concede goals from set pieces then you are going to lose games.

“We played some good stuff but we have to work on our end product. The bottom line is that I do not like losing matches and we will address that.”

Bristol City head coach Lee Johnson:

“It is important for us to get a win after a poor result. We were up against a good side, but we showed that we can compete.

“If you look at the game as a whole, we could have won by a couple more, because we had the chances. There were some outstanding performances out there, particularly from some of the younger players.

“There were some really good individual performances but, in the end, this was about us as a team and we have come out with a really good performance and a really good win.